Factors (e.g., coronary sinus obstructions, absence of a suitable cardiac vein, high thresholds, or phrenic nerve stimulation) warrant the need for an alternative to a transvenous approach to the implantation of some or all left ventricle (“LV”), left atrial (“LA”), right atrial (“RA”) and right ventricle (“RV”) leads in congestive heart failure (“CHF”) patients in need of cardiac rhythm treatment (“CRT”). Historically, the alternative to a transvenous approach has entailed placement of an epicardial lead, which required invasive surgery and an associated hospital stay.
A minimally invasive pericardial approach to implanting a stimulating lead (e.g., a LV lead) has shown great promise as an alternative to the aforementioned transvenous and invasive surgery methods. In the pericardial approach, an introducer sheath is used to deliver a lead via a subxiphoid access to an implant location within the pericardial space. Visualization techniques, such as traditional fluoroscopy, MRI or endoscopy, are used to guide the introducer sheath to the implantation location within the pericardial space and to guide the final positioning of the lead.
For several reasons, the minimally invasive pericardial approach offers greater simplicity and safety as compared to the transvenous and surgical approaches to stimulation lead implantation. First, the pericardial approach does not require access to the vascular system. Second, it is minimally invasive and does not require surgical intervention and the associated general anesthesia. Third, it allows for a pathway to the entire exterior of the heart (e.g., any chamber, blood vessel or other anatomical feature of the heart) via a single entry point in the patient and in the pericardial sac.
While the pericardial approach allows for a pathway to the entire exterior of the heart, actually accessing the entire exterior of the heart via a delivery tool is another matter. Consequently, there is a need in the art for an introducer sheath that readily facilitates accessing the entire, or nearly the entire, exterior of the heart via a subxiphoid access. There is also a need in the art for a method of delivering a medical device or therapy to any point on the exterior of the heart.